The standardization of an image coding scheme called HEVC (High Efficiency Video Coding) by JCTVC (Joint Collaboration Team-Video Coding), which is a joint standardization organization of ITU-T and ISO/IEC, is currently under way for the purpose of improving coding efficiency more than H.264/AVC. For the HEVC standard, Committee draft as the first draft specifications was issued in February, 2012 (see, for example, Non-Patent Literature 1 below).
In standardization of HEVC, methods of partitioning an image into a plurality of tiles and performing an encoding process and a decoding process on each tile have been suggested (see, for example, Non-Patent Literature 2 below). The tile partitioning enables an advanced parallel process performed to improve a processing speed to be performed and matching with a MTU (Maximum Transmission Unit) size of a transmitted encoded stream to be performed easily.